The project replaces wet film with digital cameras and is part of an upgrade of 250 cameras by October.

What's happening?

TfL is replacing the older speed cameras on the road that runs from Sunbury into Twickenham through West London.

Work to install the new digital system began at the end of 2014. You may have noticed the traditional yellow speed camera being removed in the last few months and replaced by average speed cameras.

Installation was completed last month and the cameras will go live from Monday (June 13).

Speed cameras are to be replaced on the A316 in Sunbury

But why?

TfL says average speed cameras improve speed compliance between cameras along a more extensive length of road, rather than just where the camera is located, helping to "reduce the number of people killed or seriously injured".

Lilli Matson, head of surface strategy and outcome planning at TfL, said: “New digital average speed cameras are due to go live on the A316 from next week.

“The new cameras are part of our programme of upgrading old, out of date, wet-film safety cameras, and ensuring our roads continue to benefit from the safety of such installations.

"Four stretches of road, including the A316, have been identified as being better suited to the modern average speed camera system to mitigate drivers speeding and help to reduce collisions resulting in death or serious injury.”

How do they work?

Multiple cameras are set at separate locations along a stretch of road (at a minimum 200m apart) and using number plate reading technology will record the time and date of each car that passes.

A computer will then work out the average speed between the cameras to determine if the car was over the speed limit.

Will the cameras be used anywhere else?

The TfL trial includes four different locations in London.

Average speed cameras were installed on the A40 in October 2015 and will also go live on the A406 and A2 later this summer.